In mobile systems, end-user applications typically adjust to network congestion by sensing an end-to-end bandwidth between a user equipment (UE) and application server and adapting service accordingly.
An example is HTTP adaptive streaming (HAS) used in Apple™ Live Streaming, Microsoft™ Smooth Streaming/Silverlight, Adobe™ Dynamic Streaming for Flash™ and 3GPP DASH for streaming multimedia content. With HAS, the UE requests approximately 2 second content chunks, where the size of each chunk depends primarily on a time to receive a prior chunk.
In contrast, network optimization and yield management functions rely on proprietary interfaces to network elements, network probes that monitor standardized bearer path and control interfaces, or interfaces to operations, administration and maintenance (OA&M) systems to obtain network element and air-interface congestion states. Optimization and yield management functions that delay content download until the network is not busy, transcode/transrate content so it consumes less network resources or perform other similar functions are typically triggered based on the obtained congestion state.